Measurement of 137Cs in the soil in Korea by low-level background gamma-ray spectrometer

¹³⁷Cs was measured in soil samples collected in Korea from 2006 to 2008 using a low-level background gamma-ray spectrometer that was designed and developed by KRISS (Korea Research Institute of Standards and Science). The objectives of this study are to evaluate the newly developed low-level background gamma-ray spectrometer and, consequently, to provide information on the horizontal and vertical distribution of ¹³⁷Cs in Korean soil. ¹³⁷Cs concentrations in surface soil varied from 12.8 ± 0.9 to 108 ± 4 Bq kg^?1, and the vertical profiles of ¹³⁷Cs from the Nari basin in Ulleung Island in the East Sea/Sea of Japan and Seongsan Ilchulbong Peak, Jeju Island, showed a higher concentration in the surface layer that gradually decreased with depth. On the other hand, the ¹³⁷Cs concentration in soil samples collected from Bukhan Mountain National Park in Seoul showed a subsurface maximum and decreased with depth. The ¹³⁷Cs inventories in the soil column were calculated to be 1,830–4,360 Bq m^?2 with a mean of 2,770 Bq m^?2, which was the same order of magnitude as the global fallout inventories in the mid-latitude region of the Northern Hemisphere.     

Website application for calculating cesium-137 ingestion doses from consumption of locally grown foods in the Marshall Islands

Fallout deposition from the US nuclear weapons test program at Bikini and Enewetak Atolls (1946–1958) resulted in widespread nuclear fallout contamination of the northern Marshall Islands. About 85–90 % of the nuclear test-related dose delivered to resident populations is derived from ingestion of cesium-137 (¹³⁷Cs) contained in locally grown tree-crop food products. The Lawrence Livermore National Laboratory has developed a series of interactive internet applications to provide the public with an open access platform to learn more about radiological conditions in the Marshall Islands. The ingestion dose calculator application described here is one such feature whereby users can calculate hypothetical ingestion doses from ¹³⁷Cs based on interactive user input matched to environmental data on the activity concentration of ¹³⁷Cs contained in food plants such as coconut, breadfruit, Pandanus, and arrowroot. Users are asked to enter a date, an island and atoll location, a plant food type, and a daily intake amount (highlighted by the number of portions eaten per day in estimated gram equivalents). The application computes the user daily dose and the user equivalent annualized dose, and then compares the results with default settings based on dietary models developed for the Marshall Islands from independent dietary surveys. The default diets are based on a local plus imported food diet (or IA diet model) and an imported foods unavailable diet (or IUA diet model). Environmental data are decay corrected to the date entered by the user using an effective half-life of ¹³⁷Cs of 8.5 years (http://marshallislands.llnl.gov).     

Radiological status of Rongelap Island in 1999

A radiological survey and whole body counting of ¹³⁷Cs were carried out in Rongelap Island (main island) of Rongelap Atoll in July 1999. The maximum values of ¹³⁷Cs contamination and of g-ray dose rate were 39 kBq/m² and 0.033 mSv/h, respectively. The maximum a and b gross counting rates on the surface of ground were 1 cpm and 182 cpm in active area of 72 cm², respectively. Activity of ^239,240Pu for soil was 80 Bq/kg in the top 5 cm and aerial deposition was 3.4 kBq/m² in Rongelap Island in 1999. The body burden of ¹³⁷Cs was observed to be 27±11 Bq/kg for 6 workers. Assessment of external and internal annual doses (0.1 and 0.07 mSv/y) indicates that as of 1999 there is no large risk to the inhabitants of Rongelap Island from a radiological point of view. The radiological status of Rongelap Island, which was severely contaminated by the radiological fallouts of nuclear testings carried out in 1954, has improved year by year as shown by the decrease of ¹³⁷Cs. The effective halftime of ¹³⁷Cs, which is estimated to be 6.6 y is much shorter than the physical half-life of ¹³⁷Cs. Radioactive contamination in Kaballe Island, (a part of the northern islands used for farming) which is located 25 km northeast of Rongelap Island, was still high in 1999. One site nearby a beach was highly contaminated with ¹³⁷Cs, where the maximum activity of ¹³⁷Cs was 3.4 MBq/m², a-ray of 2 cpm, b-ray of 1205 cpm and g-ray of 0.73 mSv/h. Activity of ^239,240Pu in soil (n = 1) was 294 Bq/kg (top 5 cm) and 16 kBq/m².     

Combination of atomic lines and molecular bands for uranium optical isotopic analysis in laser induced plasma spectrometry

Radionuclide concentrations in wharf roaches inhabiting coastal areas of Honshu, Japan, were investigated in October 2011 and June 2012. Relative high concentrations of ^110mAg (2.1–127 Bq kg-wet^?1), ¹³⁴Cs (2.6–61 Bq kg-wet^?1), and ¹³⁷Cs (3.5–92 Bq kg-wet^?1) were detected in specimens from the eastern Honshu areas. Significantly lower ¹³⁷Cs concentrations (0.7–1.6 Bq kg-wet^?1) were detected in specimens from western and northern Honshu. The decay-corrected ¹³⁷Cs concentration was significantly inversely correlated with the distance from the Fukushima Dai-ichi Nuclear Power Plant. Thus, wharf roach may serve as a good bioindicator for monitoring radioactive contamination of its habitats.     

Radionuclides and trace elements in centipede species Scolopendra cingulata from Serbia

The adults of centipede Scolopendra cingulata from Serbia have been analyzed for ²¹⁴Bi, ¹³⁷Cs, ²²⁸Ac, ⁴⁰K, ²¹²Pb and ²¹⁴Pb activity. The top 5 cm of soil from the same locations (Novi Pazar, Izbice and P?inja) is also measured—to estimate upper limit of the soil–S. cingulata radionuclide transfer factors (i.e., S. cingulata/soil concentration ratios), as well as the total dose rate—external and internal exposure. Cesium-137 activity was found to be below (or equal to) minimum detectable activity in all 16 specimens. The highest measured ²¹⁴Bi activity was 0.1 Bq g^?1, while ²²⁸Ac—0.086 Bq g^?1, ⁴⁰K—0.12 Bq g^?1, ²¹²Pb—0.012 Bq g^?1 and ²¹⁴Pb—0.029 Bq g^?1. Bismut-214 transfer factors are found to range from <0.34 to 6, as ²²⁸Ac—from <0.4 to 3, whilst the total dose rate is found to be less than 18 μGy h^?1. The As, Se, Cd, Co, Cr, Cu, Mn, Ni, Pb, but also Zn and Fe concentrations—in three individuals, were also determined. All the elements showed concentrations in the P?inja S. cingulata significantly lower than in S. cingulata from Novi Pazar and Izbice.     

137Cs, 40K, alkali–alkaline earth element and heavy metal concentrations in wild mushrooms from Turkey

In 2002, an extensive study was performed in forest sites of Izmir. This first study results led on the one hand, to quantify of ¹³⁷Cs and ⁴⁰K concentration in mushrooms collected in the Izmir region and to a first evaluation of dose in people due to the ingestion of radionuclide-contaminated mushrooms. The mushroom concentration values varied over a wide range from below detection limit to 401 ± 4 Bq kg^?1 (dry wt) for ¹³⁷Cs. The ⁴⁰K concentration values obtained for different species of mushrooms ranged from 588 ± 26 Bq kg^?1 to 2024 ± 63 Bq kg^?1 (dry wt). The annual effective dose values due to mushroom ingestion for ¹³⁷Cs are lower than the ICRP-2007’s reference level value of 1 mSv for “existing” exposure situation. Inductively coupled plasma-mass spectrometry was used to measure many alkali–alkaline earth elements and heavy metals in mushroom samples. The relationships among the concentrations of ¹³⁷Cs and the stable elements were presented and the occurrence of metals in mushrooms was evaluated.     

Extraction of cesium in seawater off Japan using AMP-PAN resin and quantification via gamma spectroscopy and inductively coupled mass spectrometry

The March 2011 earthquake off the Japanese coast and subsequent tsunami that devastated the Fukushima Dai-Ichi nuclear power plant resulted in the largest accidental release of cesium 137 and 134 to the oceans. Seawater samples were collected in June 2011 from 30 to 600 km off the coast of Japan as part of initial mapping of the spread of contamination in the ocean. Cesium was extracted from unfiltered and filtered (<1.0 μm) seawater using an absorber based upon an organic polymer polyacrylonitrile (PAN) containing ammonium molybdophosphate (AMP) Sebesta and Stefula (J Radioanal Nucl Chem 140:15–21, 1990). The AMP-PAN resin can be counted directly using gamma spectroscopy for ¹³⁴Cs and ¹³⁷Cs. Stable ¹³³Cs was added to evaluate extraction efficiency and quantified by ICP-MS. Our 5 mL AMP-PAN resin column was on average 95 % efficient in the removal of cesium from 20 L samples at an average flow rate of 35 mL min^?1. Measured activities of ¹³⁴Cs and ¹³⁷Cs ranged from a few Bq m^?3 to >300 Bq m^?3. The extraction column can be adapted to different sample volumes and easily used in the field.     

Radionuclides from Fukushima accident in Thessaloniki, Greece (40°N) and Milano, Italy (45°)

¹³¹I, ¹³⁷Cs and ¹³⁴Cs were observed in environmental samples in Milano (40°N), Italy and Thessaloniki (45°N), Greece, soon after the nuclear accident in Fukushima, Japan. The radionuclide concentrations were determined and studied as a function of time. In Thessaloniki the ¹³¹I in air was observed for the first time on March 24, 2011. In Milano, the first evidence of Fukushima fallout has been confirmed with ¹³¹I and ¹³⁷Cs measured in wet precipitation collected 2 days later. The maximum ¹³¹I activity concentration in air of 467 ± 25 μBq m^?3, observed in Milano on April 3–4, 2011, was almost similar to the highest value of 497 ± 53 μBq m^?3 observed in Thessaloniki. The ¹³⁴Cs/¹³⁷Cs activity ratio values in air were around 1 in both regions. Soil, grass and milk samples were contaminated with ¹³¹I and ¹³⁷Cs at a low level. Finally, a dose assessment for these two areas showed clearly that the detected activities in all environmental samples were far below levels of concern.     

Radioactivity measurements in epiphytic lichens of Uludağ Mountain in Western Anatolia

Activity concentrations of gross-β, naturally occurring ²²⁶Ra, ²³²Th, ²¹⁰Pb, ⁷Be and anthropogenic ¹³⁷Cs in epiphytic lichens collected from Uluda? Mountain are presented and discussed with the aim of evaluating potential usability of lichens as a biomonitor. The activity concentrations of gross-β, ¹³⁷Cs, ⁴⁰K, ²²⁶Ra, ²³²Th, ²¹⁰Pb and ⁷Be in the lichen samples were found to be in the range of 177–707, 4.05–94.26, 86–211, below detection limit (BDL)—19.2, BDL—14.0, 229–872, and 72.1–220.7 Bq kg^?1 in dry weight, respectively. ¹³⁷Cs content in collected epiphytic lichens was in descending order: Parmelia sulcata > Lobaria pulmonaria > Pseudevernia furfuracea > Usnea filipendula. The best biomonitor for ¹³⁷Cs among the lichen species used in this study was determined as Parmelia sulcata. Pearson’s correlation coefficient was calculated between ¹³⁷Cs and ⁴⁰K activity concentrations using a statistical package program (SPSS ver. 17.0) and a negative correlation value (R = ?0,323, p = 0,222) was obtained. The highest ²²⁶Ra and ²³²Th activity concentrations were found in Bo?azova Yaylas? which has a geological structure including granitic rocks. It was found that ¹³⁷Cs and ⁷Be activity concentrations in species demonstrated an inverse behaviour. The effect of mean annual precipitation and temperature on ⁷Be activity concentration was determined using multi regression analysis. Also, correlations between the ¹³⁷Cs and ⁷Be, and ⁴⁰K and ⁷Be were investigated.     

Distribution of 137Cs and 134Cs in the North Pacific Ocean: impacts of the TEPCO Fukushima-Daiichi NPP accident

Impact of the TEPCO Fukushima-Daiichi NPP accident, FNPP1, to the North Pacific Ocean occurred through two pathways, namely direct release and atmospheric deposition to wide ocean surface. We collected more than 100 seawater samples in the North Pacific Ocean in April and May 2011 by seven commercial ships as VOS. Since the sample volume was 2 l each, we measured radiocaesium activity at Ogoya Underground Facility to obtain reliable activity. ¹³⁷Cs was detected at all stations and ¹³⁴Cs was detected at most of the stations in the North Pacific Ocean. The ¹³⁷Cs activity ranged from around 1 to 1,000 Bq m^?3 with activity ratios of ¹³⁴Cs/¹³⁷Cs close to 1 which is a signature of radiocaesium originated from the FNPP1 accident. At east of the International Date Line north of 40°N in the Pacific Ocean in April 2011, the ¹³⁴Cs activity ranged from 2 to 12 Bq m^?3.     

An evaluation of activated bismuth isotopes in environmental samples from the former Western Pacific Proving Grounds

²⁰⁷Bi (T _1/2 = 32.2 y) was generated by activation of weapons material during a few "clean" nuclear tests at the U.S. Western Pacific Proving Grounds of Enewetak and Bikini Atolls. The radionuclides first appeared in the Enewetak environment during 1958 and in the environment of Bikini during 1956. Crater sediments from Bikini with high levels of ²⁰⁷Bi were analyzed by gamma-spectrometry in an attempt to determine the relative concentrations of ²⁰⁸Bi (T _1/2 = 3.68·10⁵ y). The bismuth isotopes were probably generated during the "clean", 9.3 Mt Poplar test held on 7/12/58. The atom ratio of ²⁰⁸Bi to ²⁰⁷Bi (R value) ranges from 12 to over 200 in sections of core sediments from the largest nuclear crater at Bikini atoll. The presence of bismuth in the device is suggested to account for R values in excess of 10.     

Environmental radioactivity measurements in north–western Greece following the Fukushima nuclear accident

The impact of the Fukushima nuclear accident in north–western Greece was assessed through an environmental monitoring programme activated by the Nuclear Physics Laboratory of the University of Ioannina. Measurements of ¹³¹I were carried out in atmospheric particulate, ovine milk and grass samples. In daily aerosol samplings, radioiodine was first detected on March 25–26, 2011 and reached maximum levels, up to 294 μBq m^?3, between April 2 and April 4, 2011. In ovine milk samples, ¹³¹I concentrations ranged from 2.0 to 2.7 Bq L^?1 between April 2 and April 6, 2011, while an average activity of 2.7 Bq kg^?1 was measured in grass samples on April 4, 2011. The ^134,137Cs isotopes were below detection limits in all samples and could only be determined in the air, by analysis of multiple daily filters. A maximum average activity concentration of ¹³⁷Cs amounting to 24 μBq m^?3 was measured during the period from April 5 to April 9, 2011, with the ¹³⁴Cs/¹³⁷Cs activity ratio being close to unity. Activity concentrations were consistent with measurements conducted in other parts of the country and were well below those reported in May 1986 after the Chernobyl accident. The committed effective dose to the whole body and to the thyroid gland from inhalation of ¹³¹I was estimated for the adult and infant population and was found to be of no concern for the public health.     

A preliminary study on 226Ra, 232Th, 40K and 137Cs activity concentrations in vegetables and fruits frequently consumed by inhabitants of Elazığ Region, Turkey

Determining radioactivity levels in foodstuffs is of great importance for the protection of human health. In addition, the literature includes few studies related to this subject in Turkey. In this study, gamma spectroscopic system was used in order to measure ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs activity concentrations in vegetables and fruits produced in Elaz?? Region. The average activity concentrations in vegetables was calculated as 0.64 ± 0.26 Bq kg^?1 for ²²⁶Ra, 0.65 ± 0.14 Bq kg^?1 for ²³²Th, 13.98 ± 1.22 Bq kg^?1 for ⁴⁰K, and 0.54 ± 0.04 Bq kg^?1 for ¹³⁷Cs. The average activity concentrations in fruits were 1.52 ± 0.34, 0.98 ± 0.23, 18.66 ± 1.13 and 0.59 ± 0.16 Bq kg^?1, respectively for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs. Total committed effective dose value was determined as 20 and 30.55 μSv y^?1, respectively for vegetables and fruits. The findings were compared with previous data reported for Turkey and other regions of the world.     

Determination of 135Cs in nuclear power plant wastes by ICP-MS and k 0-NAA

A radiochemical method for the determination of ¹³⁵Cs in radioactive wastes has been adopted/developed. For the separation of cesium from other elements ammonium-molybdophosphate precipitation and cation exchange chromatography were used. The chemical yield of the method was about 60–100 %. ¹³⁵Cs was measured by two methods. In neutron activation analysis (NAA), Cs was irradiated with reactor neutrons. ¹³⁶Cs was detected by gamma spectrometry, wherefrom the activity/mass of ¹³⁵Cs was calculated according to the k ₀-standardization technique. The Cs containing fractions were measured by inductive coupled plasma mass spectrometry, as well. NAA and ICP-MS techniques were comparatively evaluated and a good agreement between the results was found. The activity concentration of ¹³⁵Cs in a couple of waste samples originating from VVER-440 type nuclear reactors was in the range of 1–5 Bq L^?1 (20–120 ng L^?1) while ¹³⁷Cs activity concentrations varied between 0.1 and 1 MBq L^?1.     

Dose rates and seasonal variations of 238U, 232Th, 226Ra 40K and 137Cs radionuclides in soils along Thrace, Turkey

Concentrations of ²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K and ¹³⁷Cs are measured in collected soil samples from various locations in the Thrace region of Turkey. The activity concentrations range from 12.82 to 101.75 Bq kg^?1 d.w. (dry weight) for ²³⁸U, from 5.16 to 73.34 Bq kg^?1 d.w. for ²³²Th, from 185.54 to 5399 Bq kg^?1 d.w. for ⁴⁰K and from 11.42 to 90.73 Bq kg^?1 d.w. for ²²⁶Ra. In addition to naturally occurring radionuclides, ¹³⁷Cs activity concentration is determined between 3.05 and 46.78 Bq kg^?1 d.w. for soil samples. Determination of the radiological hazard is achieved through calculations of the external terrestrial gamma dose rate in air (nGy h^?1) and annual effective dose rate (mSv year^?1) and the results are compared with the similar works in different countries.     

Radioactivity levels and radiation hazard of healing mud from San Diego River, Cuba

Healing mud core samples were collected in the San Diego River (Southwest Cuba), in order to determine the behaviour of the radioactivity levels of ²²⁶Ra, ¹³⁷Cs, ²³²Th and ⁴⁰K and to evaluate their possible radiological impact on peloide therapeutic uses. The radionuclide concentration ranges in healing mud profiles on Bq kg^?1 dry weight varied as follows: ²²⁶Ra = 22–26, ¹³⁷Cs = 4.6–33.0, ²³²Th = 18–31 and ⁴⁰K = 208–433. The calculated average radium equivalent activity (82 Bq kg^?1), total absorbed dose rate (40 nGy h^?1), external hazard index (0.23), annual gonadal dose equivalent (280 μSv h^?1) and annual effective dose equivalent (48.5 μSv y^?1) are less than international recommended values. Hence, the levels of radioactivity in healing muds from San Diego River are not an impediment for its use for medical proposes.     

The evaluation of 137Cs radioactivities in soils taken from the Babia Góra National Park

The aim of this work was to determine ¹³⁷Cs and ⁴⁰K radioactivities in soil samples taken from the Babia Góra National Park (BPN) in south Poland. The cluster analysis (CA) and principal component analysis (PCA) were used to discuss the obtained data. 10 cm thick soil cores were collected from the BPN area. Each sample was divided into three sub-samples. The samples were dried, homogenized and packed in polyethylene containers. The radioactivities of ¹³⁷Cs and ⁴⁰K were measured by means of gamma spectrometry. It was found that ¹³⁷Cs radioactivity in the whole 10 cm soil cores was in the range from 1,916 to 28,551 Bq m^?2. The radioactivity of ⁴⁰K varied from 1,642 to 25,654 Bq m^?2. Using CA it was possible to diverse the soils taking into account soil types. By use of the PCA method, it was chosen three factors which are appropriate to characterize researched parameters.     

Radiometric analysis of rock and soil samples of Leepa Valley; Azad Kashmir, Pakistan

In this article, we present results obtained from a radiometric survey that was conducted in the Leepa Valley of Azad Jammu & Kashmir, Pakistan. The purpose of current study is to appraise the radioactivity levels and the associated health hazards due to the terrestrial radionuclide in soil and rock samples. In this regard, 16 soil and 17 rock samples were collected from different locations of the Leepa Valley. After processing the samples, activity concentrations of primordial (²³²Th, ²²⁶Ra and ⁴⁰K) and anthropogenic (¹³⁷Cs) radionuclides were determined using a P-type coaxial high purity germanium detector. From the results obtained the mean activity concentrations of radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the soil samples were found to be 31.25 ± 0.46, 44.1 ± 1.07 and 575 ± 8.89 Bq kg^?1 respectively. Whilst, in rock samples ²²⁶Ra, ²³²Th and ⁴⁰K mean activities were found as 28.46 ± 0.45, 48.63 ± 1.12 and 666.7 ± 9.39 Bq kg^?1, respectively. The ¹³⁷Cs concentration level in soil and rock samples is found to be 15.04 ± 0.29 and 5.7 ± 0.16 Bq kg^?1, respectively. The average radium equivalent activity (R _aeq) was found as 143.16 and 142.93 Bq kg^?1 in soil and rock samples, respectively. These findings are less than the recommended safe value of 370 Bq kg^?1 as given in OECD report (1979). The values of external (H _ex) and internal hazard index (H _in) are also less than unity. Mean value of absorbed dose rate was found as 69.78 nGy h^?1 for the soil samples, which is in good agreement with the world wide average value (70 nGy h^?1). Mean value of absorbed dose rate from rock samples was found as 70.01 nGy h^?1. Mean values of the annual effective dose is also lower than the values reported for different other countries of the world.     

Determination and spatial distribution of <Superscript>137</Superscript>Cs in soils,mosses and lichens near Kavanayen,Venezuela

The activity of ¹³⁷Cs was determined in soils, mosses, lichens and other vegetation along the Caruay River and near the town of Kavanayen. The range of values for the soils was from <1.2 Bq·kg⁻¹ of ¹³⁷Cs (our detection limit) to 14.1 Bq·kg⁻¹. The range of ¹³⁷Cs activities in the mosses ranged from 9.9 to 17.9 Bq·kg⁻¹ with a mean value of 13.4±4 Bq·kg⁻¹; all the moss samples were found along the river. While the ¹³⁷Cs activities in the lichens ranged from 9.1 to 29.8 Bq·kg⁻¹; the two values along the river were about three factors higher than the one near Kavanayen. It was concluded that the ¹³⁷Cs activities in the soils, mosses and lichens are much higher along the river in respect to the nearby town of Kavanayen.     

The Sorben-Tec system for rapid dosimetric evaluation of <Superscript>137</Superscript>Cs in drinking water

The Sorben-Tec system was developed for rapid evaluation of ¹³⁷Cs in drinking water using a domestic personal dosimeter or beta-radiometer. Linear calibration curves were obtained for dosimetric and beta-radiometric measurement of caesium. In case of 20 L drinking water sample, detection limits of ¹³⁷Cs were found to be 12.3 and 2.0 Bq L^?1 for dosimetric and beta-radiometric measurement respectively. This system is recommended for using by non-professionals who are living at radioactively contaminated areas or near nuclear power plants.